The famous catchphrase uttered by Doc Brown: "Great Scott!" is often associated with Zack, seeing how his last name is "Scott".
Peter humorously made several references to "Back to the Future" in the chat box in a video where BVGamer was able to get on the Scottland server, while other Scottland players were focused on getting rid of BVGamer.
During one of Zack's videos, when Ashley'sClock Tower was barely completed, someone suggested having lightning strike it, in reference to when lightning had to strike the clock tower of Hill Valley in order for the DeLorean to go back to the future.
Ashley's Clock Tower is also named the Great Scott.
In some episodes you can hear Brett's text message alert. The alert is "Something's Changed" from Back To The Future.
He also has a Marty McFly costume which you can see in the background of webcam episodes.